A separation device for a lithium-containing leach solution

Abstract

This invention discloses a separation device for lithium-containing leachate, relating to the field of lithium extraction technology from lepidolite. The device includes a column comprising an electrolysis section and a separation section. In the electrolysis section, the anode column and a first anion exchange membrane form a first cavity, and the first anion exchange membrane and a cathode plate form a second cavity. The electrolysis section has an inlet communicating with the second cavity. In the separation section, the cathode column and the second anion exchange membrane form a third cavity, and the second anion exchange membrane and the anode plate form a fourth cavity. The separation section has an outlet communicating with the third cavity. The cathode column and the anode plate are covered with an insulating layer. The first cavity communicates with the third cavity, and the second cavity communicates with the fourth cavity. The lithium-containing leachate separation device provided by this invention can separate sulfate and chloride anions from the leachate. Chlorine escapes as a gas, and the leachate after chloride ion separation flows out as sulfate, thereby removing chloride ions from the leachate and reducing the requirements for subsequent process equipment.

Description

Technical Field

[0001] This invention relates to the field of lithium extraction technology from lepidolite, and in particular to a separation device for lithium-containing leachate. Background Technology

[0002] Currently, there are dozens of methods for producing lithium salts using solid minerals as raw materials. These methods basically involve roasting enriched ores together with various alkalis, salts, or mixtures thereof, and then further processing the roasted material using different methods to produce lithium, rubidium, and cesium salts.

[0003] To efficiently utilize lithium, rubidium, and cesium in lepidolite, a mixed roasting process using the chloride-sulfate method is typically employed. This process comprehensively utilizes lithium, rubidium, and cesium in lepidolite. However, due to the introduction of sulfates and chlorides, the resulting leachate contains both sulfate and chloride anions. The presence of chloride ions places stringent requirements on subsequent process equipment, thus necessitating a device capable of separating the two anions from the leachate. Summary of the Invention

[0004] The purpose of this invention is to provide a separation device for lithium-containing leachate to solve the problems existing in the prior art, which can separate sulfate and chloride anions from the leachate, reducing the requirements for subsequent process equipment.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a separation device for lithium-containing leachate, comprising a column, wherein the column includes an electrolysis section and a separation section arranged sequentially along an axial direction; the electrolysis section includes an anode column, a first anion exchange membrane, a cathode plate, and an electrolysis shell arranged sequentially from the axis outwards, wherein a first cavity is formed between the anode column and the first anion exchange membrane, and a second cavity is formed between the first anion exchange membrane and the cathode plate, and an inlet communicating with the second cavity is provided on the electrolysis section; the separation section includes a cathode column, a second anion exchange membrane, an anode plate, and a separation shell arranged sequentially from the axis outwards, wherein a third cavity is formed between the cathode column and the second anion exchange membrane, and a fourth cavity is formed between the second anion exchange membrane and the anode plate; an outlet communicating with the third cavity is provided on the separation section; the cathode column and the anode plate are covered with an insulating layer, and the first cavity communicates with the third cavity, and the second cavity communicates with the fourth cavity.

[0007] Preferably, the electrolysis section is provided with a first gas outlet and a second gas outlet at the end opposite to the separation section, the first gas outlet being connected to the first cavity and the second gas outlet being connected to the second cavity.

[0008] Preferably, a first fixing block is provided at one end of the electrolysis section away from the separation section. The first fixing block is detachably connected to the anode column, the first anion exchange membrane, the cathode plate, and the electrolysis shell. The first fixing block is provided with a first gas outlet and a second gas outlet.

[0009] Preferably, a second fixing block is provided at one end of the separation section away from the electrolysis section. The second fixing block is detachably connected to the cathode column, the second anion membrane, the anode plate, and the separation shell. The liquid outlet is provided on the second fixing block.

[0010] Preferably, a fifth cavity is formed between the separation shell and the anode plate, the anode plate is provided with micropores that can connect the fourth cavity and the fifth cavity, and the side of the separation shell opposite to the electrolysis section is provided with a discharge port that connects to the fourth cavity.

[0011] Preferably, a sixth cavity is formed between the electrolytic shell and the cathode plate, and the cathode plate is provided with micropores that can connect the second cavity and the sixth cavity, and the sixth cavity is connected to the fifth cavity.

[0012] Preferably, a third fixing block is provided between the electrolysis section and the separation section. One end of the third fixing block is detachably connected to the anode column, the first anion exchange membrane, the cathode plate, and the electrolysis shell, and the other end is detachably connected to the cathode column, the second anion exchange membrane, the anode plate, and the separation shell. The third fixing block is provided with a first flow channel, a second flow channel, and a third flow channel. The first flow channel connects the first cavity and the third cavity, the second flow channel connects the second cavity and the fourth cavity, and the third flow channel connects the sixth cavity and the fifth cavity.

[0013] Preferably, the cross-sections of the first anion exchange membrane, the cathode plate, the second anion exchange membrane, and the anode plate are all annular.

[0014] Preferably, regulating valves are provided at the liquid inlet, the liquid outlet, and the material outlet.

[0015] The present invention achieves the following technical effects compared to the prior art:

[0016] The lithium-containing leachate separation device provided by this invention first fills the column with pure water, then the leachate enters the second chamber through the inlet. Under the action of an electric field, chloride ions and sulfate ions pass through the first anion exchange membrane into the first chamber, while cations cannot pass through the first anion exchange membrane and accumulate in the cathode plate area. Under the action of the electric field, the first anion exchange membrane completes the separation of cations and anions. Chloride ions preferentially discharge on the anode column to generate chlorine gas, while a small amount of impurity ions Fe are generated on the cathode plate. 3+ Cu 2+ After the iron and copper ions have discharged, hydrogen ions discharge, producing hydrogen gas. The leachate gradually pushes the pure water out until the leachate containing sulfate and hydroxide ions (the hydroxide ion concentration increases after hydrogen ion discharge) enters the third chamber of the separation section, while the leachate containing cations enters the fourth chamber. Because the cathode column and anode plate are covered with an insulating layer, the separation section only performs ion separation and does not undergo an electrolytic reaction. Under the influence of the electric field, the anions in the third chamber move through the second anion exchange membrane to the anode plate and enter the fourth chamber. Cations tend to move toward the cathode column, but due to the presence of the second anion exchange membrane, cations such as lithium, sodium, potassium, rubidium, and cesium in the leachate cannot enter the region where the cathode column is located. Therefore, they can only combine with anions in the fourth chamber to form sulfates. Since the anions in the region where the cathode column is located in the third chamber migrate to the outer layer, the water discharged from the outlet is low-concentration water. This completes the separation of chloride and sulfate ions in the lithium-containing leachate, and also increases the concentration of the leachate, saving the heat required for subsequent leachate concentration, thus saving energy, protecting the environment, and reducing costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the structure of the separation device for lithium-containing leachate provided in Example 1;

[0019] Figure 2 This is a schematic diagram of the structure of the first fixing block provided in Embodiment 1;

[0020] Figure 3 This is a schematic diagram of the structure of the second fixing block provided in Embodiment 1;

[0021] Figure 4 This is a structural schematic diagram of the third fixing block provided in Embodiment 1.

[0022] Icons: 1-Separation device for lithium-containing leaching solution; 10-Column; 11-Electrolysis section; 111-Anode column; 112-First anion exchange membrane; 113-Cathode plate; 114-Electrolysis shell; 115-First chamber; 116-Second chamber; 117-Liquid inlet; 118-First gas outlet; 119-Second gas outlet; 120-Sixth chamber; 12-Separation section; 121-Cathode column; 122-Second anion exchange membrane; 123-Anode plate; 124-Separation shell; 125-Third chamber; 126-Fourth chamber; 127-Liquid outlet; 128-Fifth chamber; 129-Discharge outlet; 13-First fixing block; 14-Second fixing block; 15-Third fixing block; 151-First flow channel; 152-Second flow channel; 153-Third flow channel; 16-Regulating valve. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The purpose of this invention is to provide a separation device for lithium-containing leachate to solve the problems existing in the prior art, which can separate sulfate and chloride anions from the leachate, reducing the requirements for subsequent process equipment.

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1

[0027] This embodiment provides a separation device 1 for lithium-containing leachate. Please refer to [link to device 1]. Figure 1The system includes a column 10, which includes an electrolysis section 11 and a separation section 12 arranged sequentially along its axial direction. The electrolysis section 11 includes an anode column 111, a first anion exchange membrane 112, a cathode plate 113, and an electrolysis shell 114 arranged sequentially from the axis outwards. A first cavity 115 is formed between the anode column 111 and the first anion exchange membrane 112, and a second cavity 116 is formed between the first anion exchange membrane 112 and the cathode plate 113. An inlet 117 communicating with the second cavity 116 is provided on the electrolysis section 11. The separation section 12 includes an electrolysis section 111 and a separation section 12 arranged sequentially from the axis outwards. The cathode column 121, the second anion membrane 122, the anode plate 123, and the separation shell 124 are arranged in a secondary configuration. A third cavity 125 is formed between the cathode column 121 and the second anion membrane 122, and a fourth cavity 126 is formed between the second anion membrane 122 and the anode plate 123. An outlet 127 communicating with the third cavity 125 is provided on the separation section 12. The cathode column 121 and the anode plate 123 are covered with an insulating layer, and the first cavity 115 is communicating with the third cavity 125, and the second cavity 116 is communicating with the fourth cavity 126.

[0028] First, pure water is passed through column 10. Then, the leachate enters the second chamber 116 through inlet 117. Under the action of the electric field, chloride ions and sulfate ions pass through the first anion exchange membrane 112 and enter the first chamber 115. Cations cannot pass through the first anion exchange membrane 112 and accumulate in the cathode plate 113 area. Under the action of the electric field, the first anion exchange membrane 112 completes the separation of cations and anions. Chloride ions preferentially discharge on the anode column 111 to generate chlorine gas, while a small amount of impurity ions Fe are generated on the cathode plate 113. 3+ Cu 2+ After the iron and copper ions have discharged, hydrogen ions discharge, producing hydrogen gas. The leachate gradually pushes the pure water out until the hydrogen ions in the solution containing sulfate and hydroxide ions discharge. The leachate with increased hydroxide ions enters the third chamber 125 of the separation section 12, while the leachate containing cations enters the fourth chamber 126 of the separation section 12. Because the cathode column 121 and the anode plate 123 are covered with an insulating layer, the separation section 12 only completes ion separation and does not undergo an electrolytic reaction. Under the action of the electric field, the anions in the third chamber 125 move towards the anode plate 123 through the second anion exchange membrane 122. The cations enter the fourth chamber 126, and while there is a tendency for the cations to move toward the cathode column 121, the presence of the second anion exchange membrane 122 prevents the cations from entering the region where the cathode column 121 is located. Therefore, the cations can only combine with the anions in the fourth chamber 126 to form sulfate. Since the anions in the region where the cathode column 121 is located in the third chamber 125 migrate to the outer layer, the water discharged from the outlet 127 is low-concentration water. This not only completes the separation of chloride and sulfate ions in the lithium-containing leachate, but also increases the concentration of the leachate, saving the heat required for subsequent leachate concentration, thus saving energy, protecting the environment, and reducing costs.

[0029] Specifically, the anode column 111, the first anion membrane 112, the cathode plate 113, the cathode column 121, the second anion membrane 122, and the anode plate 123 can all be made of conventional materials; the insulating layer can be made of polytetrafluoroethylene.

[0030] In the optional embodiment, more preferably, the electrolysis section 11 is provided with a first gas outlet 118 and a second gas outlet 119 at one end away from the separation section 12. The first gas outlet 118 is connected to the first cavity 115, and the second gas outlet 119 is connected to the second cavity 116. Chloride gas generated by the discharge of chloride ions on the anode column 111 preferentially over sulfate ions is discharged through the first gas outlet 118, while hydrogen gas generated by the discharge of hydrogen ions on the cathode plate 113 is discharged through the second gas outlet 119.

[0031] In the optional solutions of this embodiment, a more preferred option is described in the following description: Figure 2 An electrolysis section 11 is provided with a first fixing block 13 at one end away from the separation section 12. The first fixing block 13 can be detachably connected to the anode column 111, the first anion membrane 112, the cathode plate 113, and the electrolysis shell 114. The first fixing block 13 is provided with a first gas outlet 118 and a second gas outlet 119. The first fixing block 13 facilitates assembly and fixation. The first fixing block 13 can be threadedly connected to the electrolysis shell 114 and can be plugged into the anode column 111, the first anion membrane 112, and the cathode plate 113. The anode column 111 and the cathode plate 113 can be connected to external electrodes.

[0032] In the optional solutions of this embodiment, a more preferred option is described in the following description: Figure 3 A second fixing block 14 is provided at one end of the separation section 12 away from the electrolysis section 11. The second fixing block 14 can be detachably connected to the cathode column 121, the second anion membrane 122, the anode plate 123, and the separation shell 124. The second fixing block 14 is provided with a liquid outlet 127. The second fixing block 14 facilitates assembly and fixation. The second fixing block 14 can be threadedly connected to the separation shell 124 and can be plugged into the cathode column 121, the second anion membrane 122, and the anode plate 123. The cathode column 121 and the anode plate 123 can be connected to external electrodes.

[0033] In the optional embodiment, more preferably, a fifth cavity 128 is formed between the separation shell 124 and the anode plate 123. The anode plate 123 is provided with micropores that can connect the fourth cavity 126 and the fifth cavity 128. The side of the separation shell 124 facing away from the electrolysis section 11 is provided with a discharge port 129 that connects to the fourth cavity 126. By providing the fifth cavity 128 and communicating with the fourth cavity 126, sulfate ions and cations in the leachate can generate sulfate in the fourth cavity 126. The leachate is discharged through the discharge port 129 in the form of sulfate.

[0034] In an optional embodiment, more preferably, a sixth cavity 120 is formed between the electrolytic shell 114 and the cathode plate 113. The cathode plate 113 is provided with micropores that can connect the second cavity 116 and the sixth cavity 120. The sixth cavity 120 is connected to the fifth cavity 128. The cations in the second cavity 116 can enter the sixth cavity 120 and flow into the fifth cavity 128, and then flow into the fourth cavity 126 through the micropores.

[0035] In the optional solutions of this embodiment, a more preferred option is described in the following description: Figure 4 A third fixing block 15 is provided between the electrolysis section 11 and the separation section 12. One end of the third fixing block 15 can be detachably connected to the anode column 111, the first anion membrane 112, the cathode plate 113, and the electrolysis shell 114, and the other end can be detachably connected to the cathode column 121, the second anion membrane 122, the anode plate 123, and the separation shell 124. The third fixing block 15 is provided with a first flow channel 151, a second flow channel 152, and a third flow channel 153. The first flow channel 151 connects the first cavity 115 and the third flow channel 153. Cavity 125, second flow channel 152 connects second cavity 116 and fourth cavity 126, third flow channel 153 connects sixth cavity 120 and fifth cavity 128; by setting third fixing block 15, it is convenient to connect and communicate between electrolysis section 11 and separation section 12, wherein the third fixing block 15 can be threadedly connected to electrolysis shell 114 and separation shell 124, and can be inserted into anode column 111, first anion membrane 112, cathode plate 113, cathode column 121, second anion membrane 122 and anode plate 123.

[0036] Specifically, the first flow channel 151, the second flow channel 152 and the third flow channel 153 can be configured as connecting holes, and in this embodiment, the first fixing block 13, the second fixing block 14 and the third fixing block 15 can be made of insulating materials, such as polytetrafluoroethylene, polyvinyl chloride, polyethylene, etc.

[0037] In the optional embodiments of this example, it is more preferred that the cross-sections of the first anion membrane 112, the cathode plate 113, the second anion membrane 122, and the anode plate 123 are all annular, that is, the first anion membrane 112, the cathode plate 113, the second anion membrane 122, and the anode plate 123 are all cylindrical, and the cathode plate 113 and the anode plate 123 are fine-pore cylindrical electrode plates.

[0038] In the optional scheme of this embodiment, it is more preferred that a regulating valve 16 is provided at the liquid inlet 117, the liquid outlet 127 and the material outlet 129; the liquid inlet, liquid outlet and material outlet speeds are controlled by controlling the regulating valve 16.

[0039] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A separation device for lithium-containing leachate, characterized in that: It includes a column (10), which includes an electrolysis section (11) and a separation section (12) arranged sequentially along the axial direction. The electrolysis section (11) includes an anode column (111), a first anion exchange membrane (112), a cathode plate (113), and an electrolysis shell (114) arranged sequentially from the axis outward. A first cavity (115) is formed between the anode column (111) and the first anion exchange membrane (112), and a second cavity (116) is formed between the first anion exchange membrane (112) and the cathode plate (113). An inlet (117) communicating with the second cavity (116) is provided on the electrolysis section (11). The separation section (12) includes a cathode column (121), a second anion membrane (122), an anode plate (123), and a separation shell (124) arranged sequentially from the axis outward. A third cavity (125) is formed between the cathode column (121) and the second anion membrane (122), and a fourth cavity (126) is formed between the second anion membrane (122) and the anode plate (123). An outlet (127) communicating with the third cavity (125) is provided on the separation section (12). The cathode column (121) and the anode plate (123) are covered with an insulating layer, and the first cavity (115) is communicating with the third cavity (125), and the second cavity (116) is communicating with the fourth cavity (126). The leachate enters the second chamber (116) through the inlet (117). Under the action of the electric field, chloride ions and sulfate ions pass through the first anion exchange membrane (112) and enter the first chamber (115). Cations cannot pass through the first anion exchange membrane (112). The leachate containing sulfate and hydroxide anions enters the third chamber (125) of the separation section (12). The leachate containing cations enters the fourth chamber (126) of the separation section (12). Under the action of the electric field, the anions in the third chamber (125) move through the second anion exchange membrane (122) to the anode plate (123) and enter the fourth chamber (126). The cations combine with the sulfate ions in the leachate in the fourth chamber (126) to form sulfate.

2. The separation device for lithium-containing leachate according to claim 1, characterized in that: The electrolysis section (11) is provided with a first air outlet (118) and a second air outlet (119) at one end away from the separation section (12). The first air outlet (118) is connected to the first cavity (115), and the second air outlet (119) is connected to the second cavity (116).

3. The separation device for lithium-containing leachate according to claim 2, characterized in that: The electrolysis section (11) is provided with a first fixing block (13) at one end away from the separation section (12). The first fixing block (13) can be detachably connected to the anode column (111), the first anion membrane (112), the cathode plate (113) and the electrolysis shell (114). The first fixing block (13) is provided with a first gas outlet (118) and a second gas outlet (119).

4. The separation device for lithium-containing leachate according to claim 1, characterized in that: The separation section (12) is provided with a second fixing block (14) at one end away from the electrolysis section (11). The second fixing block (14) can be detachably connected to the cathode column (121), the second anion membrane (122), the anode plate (123) and the separation shell (124). The liquid outlet (127) is provided on the second fixing block (14).

5. The separation device for lithium-containing leachate according to claim 1, characterized in that: A fifth cavity (128) is formed between the separation shell (124) and the anode plate (123). The anode plate (123) is provided with micropores that can connect the fourth cavity (126) and the fifth cavity (128). The side of the separation shell (124) facing away from the electrolysis section (11) is provided with a discharge port (129) that connects to the fourth cavity (126).

6. The separation device for lithium-containing leachate according to claim 5, characterized in that: A sixth cavity (120) is formed between the electrolytic shell (114) and the cathode plate (113). The cathode plate (113) is provided with micropores that can connect the second cavity (116) and the sixth cavity (120), and the sixth cavity (120) is connected to the fifth cavity (128).

7. The separation device for lithium-containing leachate according to claim 6, characterized in that: A third fixing block (15) is provided between the electrolysis section (11) and the separation section (12). One end of the third fixing block (15) can be detachably connected to the anode column (111), the first anion membrane (112), the cathode plate (113) and the electrolysis shell (114), and the other end can be detachably connected to the cathode column (121), the second anion membrane (122), the anode plate (123) and the separation shell (124). The third fixing block (15) is provided with a first flow channel (151), a second flow channel (152) and a third flow channel (153). The first flow channel (151) connects the first cavity (115) and the third cavity (125), the second flow channel (152) connects the second cavity (116) and the fourth cavity (126), and the third flow channel (153) connects the sixth cavity (120) and the fifth cavity (128).

8. The separation device for lithium-containing leachate according to claim 1, characterized in that: The cross-sections of the first anion exchange membrane (112), the cathode plate (113), the second anion exchange membrane (122), and the anode plate (123) are all annular.

9. The separation device for lithium-containing leachate according to claim 5, characterized in that: A regulating valve (16) is provided at the liquid inlet (117), the liquid outlet (127), and the material outlet (129).

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